Feb 8, 2013 1:36 PM

I found this Rock while on holiday in france on the pebbled beach at Dieppe. At first It appeared to just be a pebble, but on the other side there is a hole and cavity occupied by a spherical rock. The internal rock has a larger diameter than the diameter of the hole. The diameter of the hole is approx 10mm. I was wondering if anyone could tell me anything about it?